Math Problem Solver

\[ \frac{-1}{15} + \frac{1}{20} = - \frac{1}{60} = -0.01\overline{6} \]

The sum can be computed by rewriting each term over a common denominator, where the least common denominator of \(\frac{-1}{15}\) and \(\frac{1}{20}\) is \(60\). \[ \begin{aligned} \frac{-1}{15} + \frac{1}{20} &= \frac{-1 \cdot 4}{15 \cdot 4} + \frac{1 \cdot 3}{20 \cdot 3} \\ &= \frac{-4 + 3}{60} \\ &= \frac{-1}{60} \end{aligned} \]